Portable ECG data monitoring and recording devices for use by persons in out-patient (e.g., home or work) environments have long been known. Recently, compact devices have been developed that may be worn or carried by a user for monitoring and recording ECG data and transmitting the recorded data through a telephone handset to analyzing equipment at a doctor's office or centralized location. These devices each provide certain benefits, but also suffer from various short-comings and deficiencies. These deficiencies relate primarily to either the physical size of the units or to the way in which the user is required to make contact with the electrodes and subsequently activate the recording sequence.
For example, with some of these known devices the user is required to apply the device (particularly its electrodes) to a body portion (e.g., bare chest) as soon as possible after the on-set of episodic symptoms, such as an arrhythmia. Of course, given the practical delays in finding the unit, locating a private place in which to effect the recording, opening or removing a chest-covering shirt or blouse, applying the unit to the chest and pushing the event button, transient episodic symptoms are often missed.
Other devices have attempted to overcome these "missed-event" deficiencies by requiring the user to apply two or more paste-on electrodes to their body, which electrodes are wired into the device. The unit is worn attached to the user's clothing and a memory loop feature is employed which allows the user ample time to activate the recording sequence after the on-set of episodic symptoms. Since the user actually wears attached electrodes, continuous monitoring is possible and the memory loop ensures that transient ECG data is rarely missed. Patients, however, are generally resistant to wearing a bulky device attached to their clothing, because the size and placement of the unit on the outside of clothing draws unwanted attention to the patient's medical condition. Moreover, due to the cumbersome nature of such continuous monitoring devices, the number and placement of electrodes is typically restricted. As a result, such devices are limited to obtaining ECG data readings from only one set of electrodes (i.e., from one channel).